Tag: programming languages

Questions Related to programming languages

Which of the following is correct syntax for an Abstract class ?
technology programming languages

  1. abstract double area() { }

  2. abstract double area()

  3. abstract double area();

  4. abstract double area(); { }

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Correct Option: C

Given: 11. public static void test(String str) { 12. int check = 4; 13. if (check = str.length()) { 14. System.out.print(str.charAt(check -= 1) +“, “); 15. } else { 16. System.out.print(str.charAt(0) + “, “); 17. } 18. } and the invocation: 21. test(”four”); 22. test(”tee”); 23. test(”to”); What is the result?
technology programming languages

  1. r, t, t,

  2. r, e, o,

  3. Compilation fails.

  4. An exception is thrown at runtime.

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Correct Option: C

Given: 1. public class Threads5 { 2. public static void main (String[] args) { 3. new Thread(new Runnable() { 4. public void run() { 5. System.out.print(”bar”); 6. }}).start(); 7. } 8. } What is the result?

technology programming languages

  1. Compilation fails.

  2. An exception is thrown at runtime.

  3. The code executes normally and prints “bar”.

  4. The code executes normally, but nothing prints.

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Correct Option: C

AI Explanation

To answer this question, we need to understand the behavior of the code provided.

In the given code, a new thread is created using an anonymous inner class that implements the Runnable interface. The run() method in the inner class is overridden to print "bar". The start() method is then called on the newly created thread to start its execution.

When a thread is started using the start() method, it executes independently in parallel with the main thread. In this case, the newly created thread will execute the run() method and print "bar".

Therefore, the correct answer is:

C) The code executes normally and prints "bar".

Given: 1. public class TestOne { 2. public static void main (String[] args) throws Exception { 3. Thread.sleep(3000); 4. System.out.println(”sleep”); 5. } 6. } What is the result?
technology programming languages

  1. Compilation fails.

  2. An exception is thrown at runtime.

  3. The code executes normally and prints “sleep”.

  4. The code executes normally, but nothing is printed.

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Correct Option: C

foo and bar are public references available to many other threads. foo refers to a Thread and bar is an Object. The thread foo is currently executing bar.wait(). From another thread, which statement is the most reliable way to ensue that foo will stop executing wait()?
technology programming languages

  1. foo.notify();

  2. bar.notify();

  3. foo.notifyAll();

  4. Thread.notify();

  5. bar.notiFYAll();

  6. Object.notify();

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Correct Option: E

Which two are true? (Choose two.)
technology programming languages

  1. A finalizer may NOT be invoked explicitly.

  2. The finalize method declared in class Object takes no action.

  3. super.finalize() is called implicitly by any overriding finalize method.

  4. The finalize method for a given object will be called no more than

  5. The order in which finalize will be called on two objects is based on

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Correct Option: B,D

Given: 34. HashMap props = new HashMap(); 35. props.put(”key45”, “some value”); 36. props.put(”key12”, “some other value”); 37. props.put(”key39”, “yet another value”); 38. Set s = props.keySet(); 39. // insert code here What, inserted at line 39, will sort the keys in the props HashMap?
technology programming languages

  1. Arrays.sort(s);

  2. s = new TreeSet(s);

  3. Collections.sort(s);

  4. s = new SortedSet(s);

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Correct Option: B

Given: 11. public class Counter { 12. public static void main(String[] args) { 13. int numArgs = /* insert code here */; 14. } 15. } and the command line: java Counter one fred 42 Which code, inserted at line 13, captures the number of arguments passed into the program?
technology programming languages

  1. args.count

  2. args.length

  3. args.count()

  4. args.length()

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Correct Option: B

Which two are true about has-a and is-a relationships? (Choose two.)
technology programming languages

  1. Inheritance represents an is-a relationship.

  2. Inheritance represents a has-a relationship.

  3. Interfaces must be used when creating a has-a relationship.

  4. Instance variables can be used when creating a has-a relationship.

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Correct Option: A,D

Which of the following statements are true?
technology programming languages

  1. The return type for a method can be any Java type, including void

  2. An important principal of object oriented programming is implementation hiding

  3. When you perform mathematical calculations on the unlike data type, java will perform a implicit conversion to unify the types

  4. All the Above

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Correct Option: D